اسايمنت السي اف دي
This Assignment is for MSc studentsCFD Simulations of fluid flow in a 3D arterial segment with stenosis
The assignment is set and marked by Dr Quan Long
Dr Quan Long
MAIN OBJECTIVES OF THE ASSESSMENT:
· To perform flow simulations for a chosen case using commercial CFD code.
· To analyse the results by the CFD post-processor.
· To understand the influence of model geometry changing to flow patters
BRIEF DESCRIPTION OF ASSESSMENT:
Write a report presenting the simulation results for a chosen flow and analysing the results.
The chosen flow is a 3D steady blood flow. The numerical simulations are to be performed by the commercial CFD code FLUENT or CFX.
In the report, student is asked to discuss the influence of stenosis shape to the flow patterns, possible post stenosis recirculation zone and secondary flow. It is also required to comment on the specific post stenosis flow pattern and atherosclerosis development.
LEARNING OUTCOMES FOR THE ASSESSMENT
(Refer to the appropriate module learning outcomes)
· Understanding principles of modelling fluid flow by commercial CFD code.
· Conducting CFD simulation for a practical problem and perform necessary accuracy tests (mesh density independent test).
· Written presentation of the results for a practical problem.
The students will be required to:
Submit a report, which meets objectives, format and deadline as specified in this pro-forma. The report should:
· Describe the physical problem, simulation parameters and physical models used.
· Present and analyse the simulation results.
ASSESSMENT METHOD BY WHICH A STUDENT CAN DEMONSTRATE THE LEARNING OUTCOMES:
FORMAT OF THE ASSESSMENT/COURSEWORK: (Guidelines on the expected format and length of submission)
A typed report including graphs generated by FLUENT or CFX. The report should contain the sections given below:
Report structure Marking scheme
(1) Title, Student Name and Date of Submission
(4) The Physical Problem 10%
(5) Simulation Parameters 20%
(6) Results and Discussion 40%
(7) Conclusions 10%
Other sections: (1), (2), (3) and (8) 20%
The report should have the format and the length of a typical technical paper in a conference (less than 10 pages with font of 12). Appendixes are allowed. You may generate many figures from a CFD simulation, therefore, a careful plan of result presentation is required to fit the *******s into 10 pages. Also, presentation with only figures but no description and analysing is not acceptable.
ASSESSMENT DATE(S)/SUBMISSION DEADLINE(S)
The report (stapled) should be submitted to the School General Office before or on the deadline of Wednesday 12th Jan., 2011 Mid-day.
PENALTIES FOR LATE SUBMISSION:
Late submission will be subjected to current penalty scheme used in the department.
INDICATIVE READING LIST:
1. V. Sumantran and G Sovran , Vehicle Aerodynamics. Section IV “Computational Fluid Dynamics”
2. FLUENT Documents (User Manuals etc.).
3. articles which provide general geometry parameters of stenotic flow in human arteries.
Suggestions on Procedures and Presentations of Results:
· Follow the FLUENT manual and learn basic steps needed to generate structured mesh and set up a CFD problem, run CFD simulation, obtain solution and study the results using the post-processor.
· It is up to the students to decide the grid and its distribution, detailed geometry parameter, solution techniques and physical models, convergence criteria, as well as the model geometry, but these details should be given in the section “Simulation Parameters” of the report.
Date approved by Department
CFD Simulations of fluid flow in a 3D arterial segment with stenosis
This Appendix provides a brief description of the physical problem to be performed in the assignment “CFD Simulations of fluid flow in a 3D arterial segment with stenosis”. Students should use the parameters given here to perform the simulation. It is the student’s responsibility to choose the appropriate grid and physical models. The default models/values in FLUENT might be used where they are appropriate. All the simulation parameters and models used should be described in the report.
L1 L2 L3
Figure 1 Description of the model dimension.
d1, d2 are the diameter of the tube in normal and throat segment respectively in which d1 should be in the range of 6 to 8 mm. A2/A1 (ratio of area reduction) =0.4. To ensure the fully develop velocity profile, on both inlet and outlet planes, L1> 8d1 and L3 > 15d1. Two geometry models need to be constructed with different L2. They are L2=2d1 for the model 1 and L2=5d1 for the model 2. Students can define the shape of the stenosis by themselves. The mass flow rate will be decided in a way that the simulation Reynolds number is in the range of 250 to 550. Simulation with only one flow rate will be sufficient.